disable export=False in IPEXModel (#626)

* disable export=False in IPEXModel

* Update optimum/intel/ipex/modeling_base.py

Co-authored-by: Ella Charlaix <80481427+echarlaix@users.noreply.github.com>

* fix code style

---------

Co-authored-by: Ella Charlaix <80481427+echarlaix@users.noreply.github.com>

Author: jiqing-feng

optimum/intel/ipex/modeling_base.py

@@ -192,6 +192,11 @@ def _from_pretrained(
         subfolder: str = "",
         **kwargs,
     ):
+        if not getattr(config, "torchscript", False):
+            raise ValueError(
+                "`config.torchscript` should be set to `True`, if your model is not a TorchScript model and needs to be traced please set `export=True` when loading it with `.from_pretrained()`"
+            )
+
         # Load the model from local directory
         if os.path.isdir(model_id):
             model_cache_path = os.path.join(model_id, file_name)